gecko-dev/layout/generic/nsCanvasFrame.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* rendering object that goes directly inside the document's scrollbars */
#include "nsCanvasFrame.h"
#include "nsIServiceManager.h"
#include "nsHTMLParts.h"
#include "nsContainerFrame.h"
#include "nsCSSRendering.h"
#include "nsPresContext.h"
#include "nsStyleContext.h"
#include "nsRenderingContext.h"
#include "nsGUIEvent.h"
#include "nsStyleConsts.h"
#include "nsGkAtoms.h"
#include "nsEventStateManager.h"
#include "nsIPresShell.h"
#include "nsIScrollPositionListener.h"
#include "nsDisplayList.h"
#include "nsCSSFrameConstructor.h"
#include "nsFrameManager.h"
// for focus
#include "nsIScrollableFrame.h"
#include "nsIDocShell.h"
#ifdef DEBUG_rods
//#define DEBUG_CANVAS_FOCUS
#endif
nsIFrame*
NS_NewCanvasFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsCanvasFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsCanvasFrame)
NS_QUERYFRAME_HEAD(nsCanvasFrame)
NS_QUERYFRAME_ENTRY(nsCanvasFrame)
NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
void
nsCanvasFrame::DestroyFrom(nsIFrame* aDestructRoot)
{
DestroyAbsoluteFrames(aDestructRoot);
nsIScrollableFrame* sf =
PresContext()->GetPresShell()->GetRootScrollFrameAsScrollable();
if (sf) {
sf->RemoveScrollPositionListener(this);
}
nsContainerFrame::DestroyFrom(aDestructRoot);
}
void
nsCanvasFrame::ScrollPositionWillChange(nscoord aX, nscoord aY)
{
if (mDoPaintFocus) {
mDoPaintFocus = false;
PresContext()->FrameManager()->GetRootFrame()->InvalidateFrameSubtree();
}
}
NS_IMETHODIMP
nsCanvasFrame::SetHasFocus(bool aHasFocus)
{
if (mDoPaintFocus != aHasFocus) {
mDoPaintFocus = aHasFocus;
PresContext()->FrameManager()->GetRootFrame()->InvalidateFrameSubtree();
if (!mAddedScrollPositionListener) {
nsIScrollableFrame* sf =
PresContext()->GetPresShell()->GetRootScrollFrameAsScrollable();
if (sf) {
sf->AddScrollPositionListener(this);
mAddedScrollPositionListener = true;
}
}
}
return NS_OK;
}
NS_IMETHODIMP
nsCanvasFrame::SetInitialChildList(ChildListID aListID,
nsFrameList& aChildList)
{
NS_ASSERTION(aListID != kPrincipalList ||
aChildList.IsEmpty() || aChildList.OnlyChild(),
"Primary child list can have at most one frame in it");
return nsContainerFrame::SetInitialChildList(aListID, aChildList);
}
NS_IMETHODIMP
nsCanvasFrame::AppendFrames(ChildListID aListID,
nsFrameList& aFrameList)
{
NS_ASSERTION(aListID == kPrincipalList ||
aListID == kAbsoluteList, "unexpected child list ID");
NS_PRECONDITION(aListID != kAbsoluteList ||
mFrames.IsEmpty(), "already have a child frame");
if (aListID != kPrincipalList) {
// We only support the Principal and Absolute child lists.
return NS_ERROR_INVALID_ARG;
}
if (!mFrames.IsEmpty()) {
// We only allow a single principal child frame.
return NS_ERROR_INVALID_ARG;
}
// Insert the new frames
NS_ASSERTION(aFrameList.FirstChild() == aFrameList.LastChild(),
"Only one principal child frame allowed");
#ifdef NS_DEBUG
nsFrame::VerifyDirtyBitSet(aFrameList);
#endif
mFrames.AppendFrames(nsnull, aFrameList);
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eTreeChange,
NS_FRAME_HAS_DIRTY_CHILDREN);
return NS_OK;
}
NS_IMETHODIMP
nsCanvasFrame::InsertFrames(ChildListID aListID,
nsIFrame* aPrevFrame,
nsFrameList& aFrameList)
{
// Because we only support a single child frame inserting is the same
// as appending
NS_PRECONDITION(!aPrevFrame, "unexpected previous sibling frame");
if (aPrevFrame)
return NS_ERROR_UNEXPECTED;
return AppendFrames(aListID, aFrameList);
}
NS_IMETHODIMP
nsCanvasFrame::RemoveFrame(ChildListID aListID,
nsIFrame* aOldFrame)
{
NS_ASSERTION(aListID == kPrincipalList ||
aListID == kAbsoluteList, "unexpected child list ID");
if (aListID != kPrincipalList || aListID != kAbsoluteList) {
// We only support the Principal and Absolute child lists.
return NS_ERROR_INVALID_ARG;
}
if (aOldFrame != mFrames.FirstChild())
return NS_ERROR_FAILURE;
// It's our one and only child frame
// Damage the area occupied by the deleted frame
// The child of the canvas probably can't have an outline, but why bother
// thinking about that?
Invalidate(aOldFrame->GetVisualOverflowRect() + aOldFrame->GetPosition());
// Remove the frame and destroy it
mFrames.DestroyFrame(aOldFrame);
PresContext()->PresShell()->
FrameNeedsReflow(this, nsIPresShell::eTreeChange,
NS_FRAME_HAS_DIRTY_CHILDREN);
return NS_OK;
}
nsRect nsCanvasFrame::CanvasArea() const
{
// Not clear which overflow rect we want here, but it probably doesn't
// matter.
nsRect result(GetVisualOverflowRect());
nsIScrollableFrame *scrollableFrame = do_QueryFrame(GetParent());
if (scrollableFrame) {
nsRect portRect = scrollableFrame->GetScrollPortRect();
result.UnionRect(result, nsRect(nsPoint(0, 0), portRect.Size()));
}
return result;
}
void
nsDisplayCanvasBackground::Paint(nsDisplayListBuilder* aBuilder,
nsRenderingContext* aCtx)
{
nsCanvasFrame* frame = static_cast<nsCanvasFrame*>(mFrame);
nsPoint offset = ToReferenceFrame();
nsRect bgClipRect = frame->CanvasArea() + offset;
if (NS_GET_A(mExtraBackgroundColor) > 0) {
aCtx->SetColor(mExtraBackgroundColor);
aCtx->FillRect(bgClipRect);
}
nsCSSRendering::PaintBackground(mFrame->PresContext(), *aCtx, mFrame,
mVisibleRect,
nsRect(offset, mFrame->GetSize()),
aBuilder->GetBackgroundPaintFlags(),
&bgClipRect);
}
/**
* A display item to paint the focus ring for the document.
*
* The only reason this can't use nsDisplayGeneric is overriding GetBounds.
*/
class nsDisplayCanvasFocus : public nsDisplayItem {
public:
nsDisplayCanvasFocus(nsDisplayListBuilder* aBuilder, nsCanvasFrame *aFrame)
: nsDisplayItem(aBuilder, aFrame)
{
MOZ_COUNT_CTOR(nsDisplayCanvasFocus);
}
virtual ~nsDisplayCanvasFocus() {
MOZ_COUNT_DTOR(nsDisplayCanvasFocus);
}
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap)
{
*aSnap = false;
// This is an overestimate, but that's not a problem.
nsCanvasFrame* frame = static_cast<nsCanvasFrame*>(mFrame);
return frame->CanvasArea() + ToReferenceFrame();
}
virtual void Paint(nsDisplayListBuilder* aBuilder,
nsRenderingContext* aCtx)
{
nsCanvasFrame* frame = static_cast<nsCanvasFrame*>(mFrame);
frame->PaintFocus(*aCtx, ToReferenceFrame());
}
NS_DISPLAY_DECL_NAME("CanvasFocus", TYPE_CANVAS_FOCUS)
};
NS_IMETHODIMP
nsCanvasFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
nsresult rv;
if (GetPrevInFlow()) {
DisplayOverflowContainers(aBuilder, aDirtyRect, aLists);
}
// Force a background to be shown. We may have a background propagated to us,
// in which case GetStyleBackground wouldn't have the right background
// and the code in nsFrame::DisplayBorderBackgroundOutline might not give us
// a background.
// We don't have any border or outline, and our background draws over
// the overflow area, so just add nsDisplayCanvasBackground instead of
// calling DisplayBorderBackgroundOutline.
if (IsVisibleForPainting(aBuilder)) {
rv = aLists.BorderBackground()->AppendNewToTop(new (aBuilder)
nsDisplayCanvasBackground(aBuilder, this));
NS_ENSURE_SUCCESS(rv, rv);
}
nsIFrame* kid;
for (kid = GetFirstPrincipalChild(); kid; kid = kid->GetNextSibling()) {
// Put our child into its own pseudo-stack.
rv = BuildDisplayListForChild(aBuilder, kid, aDirtyRect, aLists);
NS_ENSURE_SUCCESS(rv, rv);
}
#ifdef DEBUG_CANVAS_FOCUS
nsCOMPtr<nsIContent> focusContent;
aPresContext->EventStateManager()->
GetFocusedContent(getter_AddRefs(focusContent));
bool hasFocus = false;
nsCOMPtr<nsISupports> container;
aPresContext->GetContainer(getter_AddRefs(container));
nsCOMPtr<nsIDocShell> docShell(do_QueryInterface(container));
if (docShell) {
docShell->GetHasFocus(&hasFocus);
printf("%p - nsCanvasFrame::Paint R:%d,%d,%d,%d DR: %d,%d,%d,%d\n", this,
mRect.x, mRect.y, mRect.width, mRect.height,
aDirtyRect.x, aDirtyRect.y, aDirtyRect.width, aDirtyRect.height);
}
printf("%p - Focus: %s c: %p DoPaint:%s\n", docShell.get(), hasFocus?"Y":"N",
focusContent.get(), mDoPaintFocus?"Y":"N");
#endif
if (!mDoPaintFocus)
return NS_OK;
// Only paint the focus if we're visible
if (!GetStyleVisibility()->IsVisible())
return NS_OK;
return aLists.Outlines()->AppendNewToTop(new (aBuilder)
nsDisplayCanvasFocus(aBuilder, this));
}
void
nsCanvasFrame::PaintFocus(nsRenderingContext& aRenderingContext, nsPoint aPt)
{
nsRect focusRect(aPt, GetSize());
nsIScrollableFrame *scrollableFrame = do_QueryFrame(GetParent());
if (scrollableFrame) {
nsRect portRect = scrollableFrame->GetScrollPortRect();
focusRect.width = portRect.width;
focusRect.height = portRect.height;
focusRect.MoveBy(scrollableFrame->GetScrollPosition());
}
// XXX use the root frame foreground color, but should we find BODY frame
// for HTML documents?
nsIFrame* root = mFrames.FirstChild();
const nsStyleColor* color =
root ? root->GetStyleContext()->GetStyleColor() :
mStyleContext->GetStyleColor();
if (!color) {
NS_ERROR("current color cannot be found");
return;
}
nsCSSRendering::PaintFocus(PresContext(), aRenderingContext,
focusRect, color->mColor);
}
/* virtual */ nscoord
nsCanvasFrame::GetMinWidth(nsRenderingContext *aRenderingContext)
{
nscoord result;
DISPLAY_MIN_WIDTH(this, result);
if (mFrames.IsEmpty())
result = 0;
else
result = mFrames.FirstChild()->GetMinWidth(aRenderingContext);
return result;
}
/* virtual */ nscoord
nsCanvasFrame::GetPrefWidth(nsRenderingContext *aRenderingContext)
{
nscoord result;
DISPLAY_PREF_WIDTH(this, result);
if (mFrames.IsEmpty())
result = 0;
else
result = mFrames.FirstChild()->GetPrefWidth(aRenderingContext);
return result;
}
NS_IMETHODIMP
nsCanvasFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
DO_GLOBAL_REFLOW_COUNT("nsCanvasFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
NS_FRAME_TRACE_REFLOW_IN("nsCanvasFrame::Reflow");
// Initialize OUT parameter
aStatus = NS_FRAME_COMPLETE;
nsCanvasFrame* prevCanvasFrame = static_cast<nsCanvasFrame*>
(GetPrevInFlow());
if (prevCanvasFrame) {
nsAutoPtr<nsFrameList> overflow(prevCanvasFrame->StealOverflowFrames());
if (overflow) {
NS_ASSERTION(overflow->OnlyChild(),
"must have doc root as canvas frame's only child");
nsContainerFrame::ReparentFrameViewList(aPresContext, *overflow,
prevCanvasFrame, this);
// Prepend overflow to the our child list. There may already be
// children placeholders for fixed-pos elements, which don't get
// reflowed but must not be lost until the canvas frame is destroyed.
mFrames.InsertFrames(this, nsnull, *overflow);
}
}
// Set our size up front, since some parts of reflow depend on it
// being already set. Note that the computed height may be
// unconstrained; that's ok. Consumers should watch out for that.
SetSize(nsSize(aReflowState.ComputedWidth(), aReflowState.ComputedHeight()));
// Reflow our one and only normal child frame. It's either the root
// element's frame or a placeholder for that frame, if the root element
// is abs-pos or fixed-pos. We may have additional children which
// are placeholders for continuations of fixed-pos content, but those
// don't need to be reflowed. The normal child is always comes before
// the fixed-pos placeholders, because we insert it at the start
// of the child list, above.
nsHTMLReflowMetrics kidDesiredSize;
if (mFrames.IsEmpty()) {
// We have no child frame, so return an empty size
aDesiredSize.width = aDesiredSize.height = 0;
} else {
nsIFrame* kidFrame = mFrames.FirstChild();
nsRect oldKidRect = kidFrame->GetRect();
bool kidDirty = (kidFrame->GetStateBits() & NS_FRAME_IS_DIRTY) != 0;
nsHTMLReflowState kidReflowState(aPresContext, aReflowState, kidFrame,
nsSize(aReflowState.availableWidth,
aReflowState.availableHeight));
if (aReflowState.mFlags.mVResize &&
(kidFrame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_HEIGHT)) {
// Tell our kid it's being vertically resized too. Bit of a
// hack for framesets.
kidReflowState.mFlags.mVResize = true;
}
nsPoint kidPt(kidReflowState.mComputedMargin.left,
kidReflowState.mComputedMargin.top);
// Apply CSS relative positioning
const nsStyleDisplay* styleDisp = kidFrame->GetStyleDisplay();
if (NS_STYLE_POSITION_RELATIVE == styleDisp->mPosition) {
kidPt += nsPoint(kidReflowState.mComputedOffsets.left,
kidReflowState.mComputedOffsets.top);
}
// Reflow the frame
ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowState,
kidPt.x, kidPt.y, 0, aStatus);
// Complete the reflow and position and size the child frame
FinishReflowChild(kidFrame, aPresContext, &kidReflowState, kidDesiredSize,
kidPt.x, kidPt.y, 0);
if (!NS_FRAME_IS_FULLY_COMPLETE(aStatus)) {
nsIFrame* nextFrame = kidFrame->GetNextInFlow();
NS_ASSERTION(nextFrame || aStatus & NS_FRAME_REFLOW_NEXTINFLOW,
"If it's incomplete and has no nif yet, it must flag a nif reflow.");
if (!nextFrame) {
nsresult rv = aPresContext->PresShell()->FrameConstructor()->
CreateContinuingFrame(aPresContext, kidFrame, this, &nextFrame);
NS_ENSURE_SUCCESS(rv, rv);
SetOverflowFrames(aPresContext, nsFrameList(nextFrame, nextFrame));
// Root overflow containers will be normal children of
// the canvas frame, but that's ok because there
// aren't any other frames we need to isolate them from
// during reflow.
}
if (NS_FRAME_OVERFLOW_IS_INCOMPLETE(aStatus)) {
nextFrame->AddStateBits(NS_FRAME_IS_OVERFLOW_CONTAINER);
}
}
// If the child frame was just inserted, then we're responsible for making sure
// it repaints
if (kidDirty) {
// But we have a new child, which will affect our background, so
// invalidate our whole rect.
// Note: Even though we request to be sized to our child's size, our
// scroll frame ensures that we are always the size of the viewport.
// Also note: GetPosition() on a CanvasFrame is always going to return
// (0, 0). We only want to invalidate GetRect() since Get*OverflowRect()
// could also include overflow to our top and left (out of the viewport)
// which doesn't need to be painted.
nsIFrame* viewport = PresContext()->GetPresShell()->GetRootFrame();
viewport->Invalidate(nsRect(nsPoint(0, 0), viewport->GetSize()));
} else {
nsRect newKidRect = kidFrame->GetRect();
if (newKidRect.TopLeft() == oldKidRect.TopLeft()) {
InvalidateRectDifference(oldKidRect, kidFrame->GetRect());
} else {
Invalidate(oldKidRect);
Invalidate(newKidRect);
}
}
// Return our desired size. Normally it's what we're told, but
// sometimes we can be given an unconstrained height (when a window
// is sizing-to-content), and we should compute our desired height.
aDesiredSize.width = aReflowState.ComputedWidth();
if (aReflowState.ComputedHeight() == NS_UNCONSTRAINEDSIZE) {
aDesiredSize.height = kidFrame->GetRect().height +
kidReflowState.mComputedMargin.TopBottom();
} else {
aDesiredSize.height = aReflowState.ComputedHeight();
}
aDesiredSize.SetOverflowAreasToDesiredBounds();
aDesiredSize.mOverflowAreas.UnionWith(
kidDesiredSize.mOverflowAreas + kidPt);
// Handle invalidating fixed-attachment backgrounds propagated to the
// canvas when the canvas size (and therefore the background positioning
// area's size) changes. Such backgrounds are not invalidated in the
// normal manner because the size of the original frame for that background
// may not have changed.
//
// This isn't the right fix for this issue, taken more generally. In
// particular, this doesn't handle fixed-attachment backgrounds that are *not*
// propagated. If a layer with the characteristics tested for below exists
// in a non-propagated background, we should invalidate the "corresponding"
// frame (which subsumes this special case if defined broadly). For now,
// however, this addresses the most common case. Given that this behavior has
// long been broken (non-zero percent background-size may be a new instance,
// but non-zero percent background-position is longstanding), we defer a
// fully correct fix until later.
if (nsSize(aDesiredSize.width, aDesiredSize.height) != GetSize()) {
nsIFrame* rootElementFrame =
aPresContext->PresShell()->FrameConstructor()->GetRootElementStyleFrame();
nsStyleContext* bgSC =
nsCSSRendering::FindCanvasBackground(this, rootElementFrame);
const nsStyleBackground* bg = bgSC->GetStyleBackground();
if (!bg->IsTransparent()) {
NS_FOR_VISIBLE_BACKGROUND_LAYERS_BACK_TO_FRONT(i, bg) {
const nsStyleBackground::Layer& layer = bg->mLayers[i];
if (layer.mAttachment == NS_STYLE_BG_ATTACHMENT_FIXED &&
layer.RenderingMightDependOnFrameSize()) {
Invalidate(nsRect(nsPoint(0, 0), GetSize()));
break;
}
}
}
}
}
if (prevCanvasFrame) {
ReflowOverflowContainerChildren(aPresContext, aReflowState,
aDesiredSize.mOverflowAreas, 0,
aStatus);
}
FinishReflowWithAbsoluteFrames(aPresContext, aDesiredSize, aReflowState, aStatus);
NS_FRAME_TRACE_REFLOW_OUT("nsCanvasFrame::Reflow", aStatus);
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
PRIntn
nsCanvasFrame::GetSkipSides() const
{
return 0;
}
nsIAtom*
nsCanvasFrame::GetType() const
{
return nsGkAtoms::canvasFrame;
}
NS_IMETHODIMP
nsCanvasFrame::GetContentForEvent(nsEvent* aEvent,
nsIContent** aContent)
{
NS_ENSURE_ARG_POINTER(aContent);
nsresult rv = nsFrame::GetContentForEvent(aEvent,
aContent);
if (NS_FAILED(rv) || !*aContent) {
nsIFrame* kid = mFrames.FirstChild();
if (kid) {
rv = kid->GetContentForEvent(aEvent,
aContent);
}
}
return rv;
}
#ifdef DEBUG
NS_IMETHODIMP
nsCanvasFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("Canvas"), aResult);
}
#endif